1.Technical Field
Embodiments described herein relate to a composite plating liquid, a plated member and a heat radiation component.
2. Description of Related Art
With recent requirements such as size reduction and thinning on electronic apparatus, the tendency of sealing electronic apparatus closely is increasing, as a result of which the installation spaces of heat dissipation devices in electronic apparatus are being restricted increasingly. Therefore, it is strongly desired to develop a heat radiation component capable of radiating, quickly and more efficiently, heat generated by an electronic device provided inside an electronic apparatus.
A technique is known in which a metal plate is electroplated with a metal having high thermal conductivity to construct such a heat radiation component (see e.g., JP-A-2006-28636 and JP-A-2005-89836). What is called a composite plating film containing a carbon nano-material (e.g., carbon nanotubes or carbon nanofibers) which is a far superior heat radiation material is used as the metal. JP-A-2006-28636 and JP-A-2005-89836 describe that the heat radiation performance and the thermal conductivity of a composite plating film are enhanced by adding carbon nanotubes or the like. In view of recent requirements, it is desired to develop a heat radiation component having an even superior heat radiation characteristic.
The present inventors studied the above-described related art and have found that when a heat radiation component whose surface is formed with recesses and projections, for example, to optimize the surface area is electroplated with a composite plating liquid containing a carbon nano-material (e.g., carbon nanotubes or carbon nanofibers) the recess/projection surfaces are not sufficient in electrodeposition uniformity.
In particular, the inventors have found that the plating thickness is insufficient on the recess bottom surfaces and/or the side surfaces and there is large non-uniformity between those surfaces and the projection top surfaces.
The inventors studied enthusiastically on the basis of the above knowledge, and have found a particular composite plating liquid containing a carbon nano-material (e.g., carbon nanotubes or carbon nanofibers) and completed the invention. When electroplating is performed on a metal member having a surface that has a complex recess/projection shape using the above composite plating liquid, a metal plating film having a uniform thickness is formed across the complex recess/projection shape so as to contain a sufficient amount of carbon nano-material.